[Python-ideas] Option of running shell/console commands inside the REPL

[Terry Reedy]

On 2/1/2019 9:24 AM, Ken Hilton wrote:
> Hi,
> 
> As a workaround/alternative, you can just do
> 
>      >>> import os
>      >>> os.system('dir')

For repeated use within and between sessions, put 'from os import system 
as oss' in a startup file.  Then one only needs "oss('dir')".  Note that 
'dir' only works on Windows; the unix equivalent is 'ls'.

However this will not work in a gui IDE without special handling in the 
IDE.  This docstring for os.system says "Execute the command in a 
subshell."  (It should say "Execute the command in a subshell and return 
the exitcode.")  I presume that this docstring assumes that one is 
running python is a system shell and that the subshell is a 'sub' of the 
system shell.

Anyway, the subshell expects the output, in this case, a directory 
listing, to go to an attached system console.  If one enters the above 
in IDLE's shell, the output does not appear in IDLE's shell. If one 
started IDLE in a terminal with 'python(3) -m idlelib', it goes to that 
terminal.  Otherwise, it goes to a subshell which immediately closes and 
which may or may not flash on the screen.

-- 
Terry Jan Reedy